Device for preventing induction in electrical conductors.



M. M. DAVIS. DEVICE FOR PREVENTING INDUCTION IN ELECTRICAL OONDUGTORSL APPLICATION FILED JULY 17, 1909.

Patented Apr. 19, 1910.

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WITNESSES: C%

WITNESSES:

M. M. DAVIS.

DEVIGE FOR PREVENTING INDUCTION IN ELECTRICAL GONDUOTORS.

APPLICATION FILED JULY 17, 1909.

Patented Apr. 19, 1910.

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Illn- I a m IN VEN TOR lei WW A ATTORNEY To all whom may concern:

MINOR M. DAVIS, or NEWVYORK, N. Y.-

"nEvIcn ron PREVENTING INDUCTION IN ELECTRICAL CONDUCTOBS.

Specification of Letters Patent. 7 Patented Apr, 19, 1910.

Application filed July-17, 1909. Serial No. 508,228.

Be itknown that I, LIIXORQLIZ Davis, a citizen of the United States,rcsidmg in the city of Xew York, borough of Brooklyn,

county of Kings, State of Xew York, have made certain new and useful Improvements in Devices for Preventing Induction in Electrical Conductors, of which the following is a specification.

This invention relates to a method of and means for obviating or neutralizing the evil ctiects of induction between separated, substantially parallel conductors.

The objeetof this invention. is to prevent the harmful action of conductors carrying alternating impulses of considerable strength, such as are used for power pur poses, upon conductors within inductive distance of such conductors employed for signaling purposes, such as telegraphing;

The improvements consist in employing a compensating conductor in inductive relation with respect to the disturbing cause, and placing a compensating conductor in close proximity to but insulated from a conductor connected in a signaling circuit; these conductors are subject to induction from the disturbing source. This compensating conductor is caused to react onthe circuit conductor and this re-action is gradnatcd and established so as to compensate or neutralize the action of. the disturbing source on the signaling conductor.

The improvement also consists in neutralizing induction in parallel conductors by cmployin as a conductor the metal sheath of the ca Jle inclosing the signaling conductor or conductors and a parallel compensating conductor, subjecting all of these conductors to the same inductive influence, and causing the induced impulses in said compensating conductor to react upon the signaling conductor to substantially an equal and opposite extent as compared with the disturbing cause.

There are one or more insulated conductors in parallel relation, connected in circuit with signaling apparatus. in the ordinary manner; substantially parallel with these conductors, as in the samecable, are one or more cmnpeirsating conductors; these are I connected in a circuit susceptible. of conveying induced impulses, am for this purpose there may be used a ground return circuit, or the circuit may include a condenser by the switc in series, or otherwise. One coil of a transformer 15 connected in this circuit and the otherc'oll of the transformer is connected in circuit with a conductor arranged parallel with the disturbing source, at any suitable distance therefrom; for this purpose there may be used a separate conductor or the metal sheath or armor of the cable included in a compensating circuit may be used, and the transformer is so adjusted that the compensating conductors will develop a source of alternating current. having an electromotive force ctiicient to compensate for the inductive efi'ect of the disturbing source. If the disturbing source extends parallel to the circuit conductors for a comparatively long distance there may be one or more compensating conductors arranged substantially parallel with the signal circuit. conductors for a much shorter extentbutthe electromotive force, intensity or current strength is increased, graduated or adjusted so as to compensate and neutralize the effect of the disturbing cause in the circuit conductors.

,The accompanying drawings illustrate the invention.

Figure 1 shows a disturbing alternating current. conductor in inductive relation to a. cable containing telegraph wires combined with theimprovements; Fig. 2 is a modification in which a second com )ensating oonductor performs the electrica functions of the cable sheath in Fig. 1; Fig. 3 is a modification of Fig. 2 showing a. condenser in the compensating circuit; and Fig. 4 shows a group of metal sheathed cables included in-a cable so that the cable sheaths consti- J with the ground wire 20 at one terminal and the conductor 21 .22, at the other terminal. There is a transformer 12 havin two coils 11 and 12 rendered adjustable by the contact points and tap wires engaged included in circuit with the conductor w,

1 arms 8 and a, the coil 12 is the coil 11 is included in circuit with the induce impulses through the transformer b' in the compensating conductor w; these re act upon the conductors in and the etfect may be made to accurately compensate by adjusting the electro-motive force of the induced impulse inv the conductor 10 by adjusting the coil sections of the transformer 11; the arms 8 and u being moved until the desired compensation is established.

In Fig. 2 a special conductor 10 is supported in proximity to the disturbing conductor d and connected in circuit with the coil 11 of the transformer I) thus taking the place of the cable sheath 0; in this case I ground the cablesheath at frequent intervals as shown at 30.

In Fig. 3 condensers m are included in the circuit of the conductor 10 and the conductor w, the object being to complete a circuit which will carry induced impulses in both cases.

In Fi 4 there is shown a group of metal sheathed cables each cable having one or more conductors k; these cables are insulated from each other and included in a. cable having a sheath 0 of metal as in Fig. 1. The conductors k are included in pairs or singly in conducting coverings 'w, and these coverings are used in such a cable for the compensating conductor as shown in Fig. 1.

In" the claims the term substantially coextensive? has been used to described con ductors of about the same linear extent though varying somewhat; and the term substantially parallel has been used to describe conductors having a sutliciently parallel arrangement to permit induction with out limitation to the absolutely parallel arrangement of cabled conductors.

hat I claim and desire to secure by Letters Patent is:

1. The herein described means for neutralizing inductive impulses due to a conductor.

carrying adisturbing inductive current on a signaling conductor in inductive relation thereto which consists in the combination of a compensating conductorsubstantially coextensive with and parallel to the disturbing conductor, a signaling conductor, a compensating conductor substantially parallel to and coextensive with the si naling conductor and means for establis ting .an inductive relationbetwcen said compensatin r conductors and said signaling conductor 0 substantially equal and opposite etioct as com )ared with the efiect of the disturbing con uctor.

2. The described means for neutralizing induction due to a conductor carrying a disturbing inductive current on a series of si naling conductors arranged in a cable su stantially arallcl therewith, which consists in the com ination with signaling conductors of an insulated metal sheath for said conductors, a compensating conductor included in said cable,.a circuit including said sheath conductor and means for establishing an inductive relation between the sheath circuit and compensating conductor of substantially equal and op )osite effect as compared with the 'etl'ect of the disturbing conductor.

The described means for neutralizing the efi'ect of inductive impulses in a conductor carrying a disturbing inductive current on a signaling conductor in inductive relation thereto, which consists in the combination of a signaling conductor, a compensating conductor substantially co-extensive with and parallel to the disturbing conductor, a compensating conductor substantially ar- -allel to and co-extensive with the signa ing conductor, and a transformer having one coil in one compensating conductor and another coil in another compensating conductor, substantially as described.

4. The herein described means for neutralizing the effect of inductive impulses in a. conductor carrying a disturbing inductive current on a signaling conductor in inductive relation thereto, which consists in the combination of a signaling conductor, a compensating conductor substantially coextensive with and parallel to the disturbing conductor, a con-ipcnsating conductor substantially parallel to and co-extensive with the signaling conductor, a transformer having one coil in one compensating conductor and the other coil in the other compensatin conductor and means for varying the inductive cti'ect of one coil upon the other substantially as described.'

5. The herein described means for neutralizing the eti'ect of inductive impulses in a conductor carrying a disturbing current on a signaling conductor in inductive relation thereto, which consists in the combination of a signaling conductor; a compensating conductor in inductive relation to a disturbing conductor, a compensating conductor in inductive relation to the si naling conductor, and a variable source of :lectromotive force in the last-named compensating conductor.

,MINOR M. DAVIS.

Witnesses STEWART REYNOLDS, \VILLIAM A. HAYES. 

